This invention relates to air circulation systems in large construction or farm vehicles. More particularly, this invention relates to a duct arrangement that will allow access to the air filters in a vehicle air circulation system from a single access opening.
Large construction vehicles may be equipped with an air circulation system that includes an inlet plenum supplying air to the blower assembly of the air circulation system. The inlet plenum may draw air from a plurality of sources. An inlet plenum in a large vehicle may draw a portion of its air through a fresh air vent communicating with the outside environment and the remainder of its air through a vent that recirculates air from the cab.
The vents leading into the inlet plenum are typically equipped with air filters to remove impurities from the air that is being conducted to the blower assembly. It is particularly important to have a filter on the fresh air vent in construction or farm vehicles which are often operated in dusty environments such that a large amount of impurities can be expected in the air immediately outside the vehicle.
In prior art vehicles the maintenance and cleaning of these air filters has proved to be burdensome and typically required an operator to change the filters from distinct positions. In addition, the filter on the fresh air vent frequently becomes overly clogged quite quickly due to the fact that this type of vehicle is usually operated in a dusty environment.
It is therefore an object of the present invention to provide a cab duct arrangement that will allow servicing of the two air filters from a single access opening.
It is further an object of the present invention to provide a cab duct arrangement that will possess a self cleaning feature for the fresh air filter.
Moreover, is an object of the present inventin to achieve these characteristics with a cab duct arrangement that is relatively simple and inexpensive.